Electric motors according to the prior art consist substantially of two components, namely the stator with the windings thereof and the rotor.
The stator of an electromotor is in a fixed position, while the rotor can turn relative to the stator. On the stator, winding frames, around which the enameled wires are wound, are arranged. Such windings are referred to below as winding arrangement or generally as stator winding.
The enameled wires, which are wound in each case to form a coil and which lead away from these winding frames, must be electrically connected to the conducting structure in the interior of the electric motor, so that the windings can be energized.
The electrical connection of the winding wires to the conducting structure is usually established by welding or soldering. In this context, first, the enameled wires are connected to intermediate clamps, and the intermediate clamps in turn are connected to an additional conducting structure by the connection process.
However, this has the disadvantage that the electrical connection can be affected by a defective welding. In addition, the production is relatively expensive depending on the number of the connections.
From DE 10 2015 208 425 DE, an improved solution is disclosed, in which a connecting structure for a stator and a circuit board is proposed, wherein the connecting structure has connection openings for receiving stator enameled wires, and the stator and the circuit board are electrically connected to one another. The connecting structure is characterized in that, moreover, on the circuit board, connection clamps are located, which are arranged in such a manner that the electrical connection of the circuit board to the stator is implemented in that the connection clamps are inserted into the connection openings. As an advantageous design, a solution is proposed here in which the connection clamps are arranged so that, after the insertion into the connection opening, they contact the enameled wires directly and establish a conducting connection, as a result of which the electrical connection of the stator to the circuit board is established. The connection clamps on the circuit board and the connection openings on the stator are inserted directly in one another, so that the connection clamps cut into the insulation layer of the enameled wires in the connection openings, and a conducting connection is formed, as a result of which the electrical connection of the circuit board to the stator is established.
From EP 2 557 665 A1, a stator for an electric motor is known, in particular for an external rotor motor, comprising a base body with a laminated stator core as well as with stator windings arranged on the laminated stator core, each winding having a winding wire start and a winding wire end, wherein each winding wire start is connected to contact pins, wherein the base body is overmolded with a sheath made of plastic, from which the contact pins protrude at least partially. For lowering the production technological expenditure, it is proposed that a contact holder, which together with the base body is surrounded by the sheath, is slipped over the free end of the contact pins onto the base body, wherein the contact holder, sealingly and without gap, encloses the contact pins with a sealing section.
DE 20212273 U1 relates to a stator for an electric motor, in particular for an external rotor motor, consisting of a laminated stator core with stator windings and with at least one insulation element arranged on the front side and consisting of an interconnection arrangement for interconnecting winding wires of the stator windings to electrical connection lines, wherein, in the insulation element, contact elements, implemented using the insulation displacement contact technology, are held for the contacting of the winding wires and of the connection lines.
EP 0 993 095 A1 describes a stator, the interconnection arrangement of which comprises insulation displacement contact elements which are seated in special contact chambers of the front-side insulation element on the face. In concrete terms, the contact chambers consist of at least of one multiple-contact chamber which is formed by sub-chambers, on the one hand, of the insulation element (insulation end plate) overmolded on the laminated core, and, on the other hand, of an additional wiring plate which is attached on the winding head side, in such a manner that, in the mounted state of the wiring plate, the sub-chambers are arranged adjacently next to one another, wherein they receive a common contact element connecting the sub-chambers. Here, during production, ends of the winding wires are led through the contact chamber. After all the windings have been produced, the wiring plate is placed on and fastened to the winding head side of the stator. Then, all the contact chambers are provided with insulation displacement contact elements, in that the latter are inserted into the chambers. In the process, a contacting of the winding wires extending through the contact chambers occurs automatically, in that, by means of a slot-shaped conductor receptacle, the insulation is cut through, and the wire is clamped with electrical contact (insulation displacement contact technology).
Subsequently, the external connection lines are pressed in accordance with the required interconnection of the stator into slots of the contact chambers and contact elements. Here too, the insulation of the connection lines is cut through, and as a result the electrical contact is established. It is only after this connection of the external connection lines that the additional mounting of a rotor with the shaft thereof can occur, and the motor can be run through other work steps until the manufacture thereof is completed. Thus, the external connection lines in each case have to be connected individually one after the other and, in addition, already at a very early production stage. This is disadvantageous, in particular since the further production is encumbered with the connection lines, i.e., the connection lines could impede the further course of production and mounting.
The disadvantage of the above-mentioned solutions known from the prior art is the fact that they continue to be relatively elaborate and accordingly relatively expensive in terms of the mounting, and, depending on the design, they still result in complex arrangements and a high number of parts for producing of the connections with the windings of the circuit board.